Method for improving soil quality of degraded desert grassland

Abstract

The invention discloses a method for improving soil quality of degenerated desert grassland, which comprises the following steps: uniformly mixing grass seeds with a bio-organic fertilizer, and uniformly applying the mixture into the degenerated desert grassland in a tillage-free reseeding manner; wherein the reseeding rate of the grass seeds is 3-4 kg / mu, and the grass seed combination comprises 50-60 wt% of Achyranthes bidentata, 40-50 wt% of Mongolian wheatgrass and 0-10 wt% of Astragalus adsurgens; wherein the application amount of the bio-organic fertilizer is adjusted according to the soil type: the application amount of sandy soil is 60 kg / mu, and the application amount of loam soil is 40 kg / mu; the indexes of the bio-organic fertilizer are as follows: the effective viable count is greater than or equal to 5 * 10 < 7 > / g, the bio-organic fertilizer comprises bacillus subtilis, bacillus megaterium and paenibacillus mucilaginosus, fulvic acid is greater than or equal to 12%, and organic matters are greater than or equal to 40%. Compared with the traditional fence breeding and reseeding measures, the method for improving the soil quality of the degraded desert grassland provided by the invention has the advantages that the soil bulk density can be obviously reduced, the soil water content and the soil clay particle structure can be improved, and the soil nutrients, the microorganism quantity and the enzyme activity can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and more specifically, to a method for improving the quality of degraded desert grassland soil. Background Art

[0002] Grassland accounts for about 40% of the earth's land area and is the largest type of terrestrial ecosystem on the earth. Grassland plays a vital role in natural ecosystems and provides a variety of ecosystem services, such as climate regulation, carbon fixation, soil and water conservation, and biodiversity maintenance. Grassland degradation has a series of problems such as decreased vegetation coverage and productivity, deterioration of soil physical and chemical properties, changes in spatial pattern, and reduced biodiversity. Therefore, finding an economical and effective method to improve the soil of degraded desert grassland is of great practical significance for maintaining the ecological environment and strengthening economic development. Fencing is a restoration measure for the natural recovery of degraded grassland, but the recovery cycle of fencing is long, and long-term closure will also cause vegetation to degrade again. No-tillage reseeding is a technical means of directly sowing high-quality grass seeds with strong adaptability without destroying or less destroying the original vegetation and soil of the grassland. Fertilization is an ecological restoration measure that directly improves the nutritional status of degraded grassland and quickly promotes vegetation growth. Fertilization can improve the physical and chemical properties of degraded grassland soil, improve the productivity of grassland ecosystems, and shorten the recovery process of degraded grassland. Summary of the invention

[0003] The purpose of the present invention is to provide a method for improving the soil quality of degraded desert grassland, which can effectively improve the soil quality of degraded desert grassland by adopting reseeding and applying an appropriate amount of biological organic fertilizer.

[0004] In order to achieve these purposes and other advantages according to the present invention, a method for improving the soil quality of degraded desert grassland is provided, comprising: uniformly mixing grass seeds and biological organic fertilizers, and applying them uniformly to the degraded desert grassland in a no-tillage overseeding manner;

[0005] The amount of grass seed to be sown is 3-4 kg / mu, and the grass seed combination is 50-60 wt% of Rhizoma Cynanchum, 40-50 wt% of Icegrass, and 0-10 wt% of Astragalus membranaceus.

[0006] The application amount of biological organic fertilizer is adjusted according to the soil type: the application amount for sandy soil is 60kg / mu, and the application amount for loam is 40kg / mu; the indicators of biological organic fertilizer are: effective live bacteria count ≥5×107 / g, including Bacillus subtilis, Bacillus megaterium, and Paenibacillus gelatinosa, fulvic acid ≥12%, and organic matter ≥40%.

[0007] Preferably, adjust irrigation according to climatic conditions:

[0008] In arid areas with annual precipitation less than 100 mm, drip irrigation is used. The irrigation frequency is once every 2 to 3 days during the seed germination and seedling growth stages. Each irrigation amount should make the soil moist to a depth of 10 to 15 cm. Before sowing, water retaining agent is mixed with biological organic fertilizer and grass seeds. The amount of water retaining agent is 0.5 to 1% of the seed weight. The sowing area is covered with straw or mulch film. The straw thickness is 5 to 10 cm, and the mulch film needs to be tightly sealed.

[0009] In areas with annual precipitation of 100 to 200 mm, sprinkler irrigation is used, with an irrigation frequency of once every 7 to 10 days;

[0010] In addition, in areas where the annual average temperature is less than 5°C, choose to sow in late March to early April. Before sowing, germinate the seeds and soak them in warm water for 12 to 24 hours to germinate until they turn white. Build a simple greenhouse or cover the sowing area with straw curtains. The height of the simple greenhouse is 1 to 1.5 meters, and the thickness of the straw curtains is 3 to 5 cm.

[0011] In areas where the average annual temperature is greater than 25°C, build a shade net with a shading rate of 50-70% in the sowing area during the high temperatures in summer; irrigate once in the morning and evening every day; conduct pest and disease inspections at least once a week and take timely prevention and control measures.

[0012] Preferably, the grass seed composition and the biological organic fertilizer are uniformly mixed in a mass ratio of 1:(5-20);

[0013] The mass ratio of the three kinds of Bacillus in the biological organic fertilizer is Bacillus subtilis: Bacillus megaterium: Paenibacillus gelatinous=(3-5):(2-4):1;

[0014] The raw materials for preparing the biological organic fertilizer include: 40-50% of decomposed sheep manure, 20-30% of humic acid mineral powder, 10-15% of soybean meal powder, and 5-8% of microbial agent;

[0015] In the first three years after reseeding, 5-8 kg / mu of humic acid slow-release fertilizer is applied each year, and the ratio of nitrogen, phosphorus and potassium of the slow-release fertilizer is (15-18):(8-12):(5-8).

[0016] Preferably, the grass seed composition and the biological organic fertilizer are subjected to a composite coating treatment on the grass seeds before being mixed, and the coating material is composed of the following components in weight ratio:

[0017] Humic acid chelated calcium magnesium particles loaded with attapulgite 30-40%, particle size 0.5-1mm, specific surface area ≥200m 2 / g; polyglutamic acid-sodium alginate sustained-release film 20-25%, cross-linking degree controlled at 60-80%;

[0018] 5-8% of composite flora activator, including 0.5% of L-glutamine, 1.5% of chitosan oligosaccharide, and 0.02% of indolebutyric acid; the rest is water;

[0019] The coating weight gain rate is 15-20% of the seed weight.

[0020] Preferably, the bacterial flora in the bio-organic fertilizer needs to be cultured in a targeted manner:

[0021] Stage 1: Activation in beef extract peptone medium at pH 7.0-7.5 for 24 h at 35±1°C;

[0022] The second stage: transfer to the acclimation medium containing 5% decomposed sheep manure extract, and gradually increase the NaCl concentration to 1.5%, increasing by 0.3% every 12 hours;

[0023] The third stage: screening stress-resistant strains under UV-microwave alternating stress, the parameters are: 254nm irradiation, 10min / microwave, 400W, treatment for 30s.

[0024] Preferably, the preparation of the bio-organic fertilizer comprises the following steps:

[0025] 1) Mixing the decomposed sheep manure with a C / N ratio of ≤25 and a moisture content of ≤30% with the humic acid mineral powder with an oxidation degree of ≥65% and a particle size of ≤0.075 mm at 80-90° C. for 20 minutes to form a porous matrix;

[0026] 2) Premix soybean meal powder with a protein content of ≥45% with a composite bacterial agent at a ratio of 1:0.2, and spray an atomized liquid containing 0.1% rhamnolipid to form microencapsulation granules with a particle size of 2 to 3 mm;

[0027] 3) The matrix obtained in step 1) and the particles obtained in step 2) are layered in a drum fermenter at a ratio of 7:3, the porosity of the pile is controlled to be ≥ 40%, the fermentation temperature is maintained at 50-55° C. for 72 hours, then cooled to 35° C. and matured for 24 hours;

[0028] 4) The fermentation product is screened through 4 mesh, 10 mesh and 20 mesh and then surface modified with fulvic acid concentrate with a pH of 8.5 to 9.0, and the final moisture content is adjusted to 12 to 15%.

[0029] Preferably, during no-tillage overseeding, a furrow opener is first used to dig furrows with a row spacing of 35 cm and a depth of 2 to 3 cm;

[0030] The furrow opener comprises:

[0031] A trough plate is vertically arranged, and a mounting plate for connecting with a seeder is arranged on the trough plate;

[0032] An L-shaped base plate, the vertical portion of which is connected to the groove of the groove-shaped plate, and the horizontal portion is located below the groove-shaped plate;

[0033] A pair of trenching plates, both connected to the top of the horizontal portion of the L-shaped base plate, and respectively extending downward on both sides of the horizontal portion of the L-shaped base plate to form an inverted V-shaped structure for trenching;

[0034] Among them, a pair of side walls of the grooved plate are provided with opposite first through holes, and a rotating shaft is rotatably connected in the first through hole. Both ends of the rotating shaft extend out of the grooved plate respectively, and a knife disc is connected to both ends of the rotating shaft. The knife disc is located above the grooving plate. A driving mechanism for driving the knife disc to rotate is also provided on the grooved plate, so that the knife disc can cut off the plant roots dug up from the grooving plate to its upper surface.

[0035] Preferably, the driving mechanism comprises:

[0036] A driving motor is arranged on the outer side wall of the grooved plate, the output shaft of the driving motor passes through the side wall of the grooved plate and extends into the groove of the grooved plate, and is coaxially connected with the first worm gear;

[0037] The portion of the rotating shaft located in the groove of the grooved plate is coaxially connected with a second worm gear, and the first worm gear is located directly above the second worm gear;

[0038] A vertical partition is arranged in the groove-shaped plate, and the vertical parts of the first worm gear and the L-shaped base plate are respectively located on both sides of the partition. A vertical worm is rotatably connected to the plate surface of the partition facing the first worm gear through a bracket, and the upper end of the worm is meshed with the first worm gear, and the lower end is meshed with the second worm gear.

[0039] Preferably, the vertical portion of the L-shaped substrate is located on the side of the groove of the partition plate facing the groove plate, and a first slider is slidably connected in the horizontal direction between a pair of side walls of the groove plate above the L-shaped substrate. The top end of the vertical portion of the L-shaped substrate is rotatably connected to a first screw rod, the upper end of the first screw rod extends through the first slider to above the groove plate, and the first screw rod is threadedly connected to the first slider for rotating the first screw rod to adjust the vertical position of the L-shaped substrate.

[0040] Preferably, a second slider is slidably connected in the vertical direction between a pair of side walls of the grooved plate in an area near the groove, and a second screw rod is rotatably connected to the vertical portion of the L-shaped substrate toward the end face of the groove of the grooved plate, and a rear end of the second screw rod extends through the second slider to the rear of the grooved plate, and the second screw rod is threadedly connected to the second slider for rotating the second screw rod to adjust the horizontal position of the L-shaped substrate.

[0041] The present invention includes at least the following beneficial effects: compared with traditional fencing and reseeding measures, the method for improving the soil quality of degraded desert grassland provided by the present invention can significantly reduce soil bulk density, increase soil water content and soil clay structure, and increase soil nutrients, microbial quantity and enzyme activity.

[0042] In addition, the use of a new type of furrow opener can reduce the entanglement of plant roots during the furrowing process, prevent the plant roots from being forcibly pulled out and bringing out a large amount of soil, reduce the disturbance of grassland soil, and help improve the physical properties of the soil.

[0043] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a structural schematic diagram of the furrow opener according to an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram of the structure of the L-shaped base plate and the grooved plate according to an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the structure inside the trough plate according to an embodiment of the present invention;

[0047] Figure 4 for Figure 3 A local enlarged schematic diagram of point A in the middle. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0049] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0050] <Preparation of Bio-Organic Fertilizer>

[0051] The indicators of biological organic fertilizer are: effective live bacteria count ≥ 5×107 / g, including Bacillus subtilis, Bacillus megaterium, and Paenibacillus gelatinosa, fulvic acid ≥ 12%, and organic matter ≥ 40%.

[0052] The raw materials for the preparation of biological organic fertilizer include: 50% of decomposed sheep manure, 30% of humic acid mineral powder, 15% of soybean meal powder, and 5% of microbial agent;

[0053] The mass ratio of the three kinds of Bacillus in the microbial agent is Bacillus subtilis: Bacillus megaterium: Paenibacillus gelatinus=4:3:1;

[0054] The bacterial flora in the biological organic fertilizer needs to be oriented and cultivated:

[0055] Stage 1: Activation in beef extract peptone medium at pH 7.0 for 24 h at 35 ± 1 °C;

[0056] The second stage: transfer to the acclimation medium containing 5% decomposed sheep manure extract, and gradually increase the NaCl concentration to 1.5%, increasing by 0.3% every 12 hours;

[0057] The third stage: screening stress-resistant strains under UV-microwave alternating stress, the parameters are: 254nm irradiation, 10min / microwave, 400W, treatment for 30s.

[0058] The preparation of the biological organic fertilizer comprises the following steps:

[0059] 1) Mixing the decomposed sheep manure with a C / N ratio of ≤25 and a moisture content of ≤30% with the humic acid mineral powder with an oxidation degree of ≥65% and a particle size of ≤0.075 mm at about 85° C. for 20 minutes to form a porous matrix;

[0060] 2) Premix soybean meal powder with a protein content of ≥45% with a composite bacterial agent at a ratio of 1:0.2, and spray an atomized liquid containing 0.1% rhamnolipid to form microencapsulation granules with a particle size of 2 to 3 mm;

[0061] 3) The matrix obtained in step 1) and the particles obtained in step 2) are layered in a drum fermenter at a ratio of 7:3, the porosity of the pile is controlled to be ≥ 40%, the fermentation temperature is maintained at 50-55° C. for 72 hours, then cooled to 35° C. and matured for 24 hours;

[0062] 4) The fermentation product is screened through 4 mesh, 10 mesh and 20 mesh and then surface modified with fulvic acid concentrate with pH 8.5, and the final moisture content is adjusted to 12-15%.

[0063] <Example A>

[0064] The method of the present invention was tested in a certain test area, where the annual average temperature was less than 5°C, the annual precipitation was less than 100 mm, the test site had a uniform degradation degree, the vegetation was uniform, and the test soil was sandy. The test grass species included Rhizoma Cynanchum, Rhizoma Icegrass, and Astragalus Astragali.

[0065] The experiment set up 8 treatments, namely: CK, closed-up control, no reseeding and no fertilization; A1, only no-till reseeding, no fertilization; A2, no-till reseeding + 40kg / mu of bio-organic fertilizer; A3, no-till reseeding + 60kg / mu of bio-organic fertilizer; A4, no-till reseeding + 80kg / mu of bio-organic fertilizer; A5, no-till reseeding + 60kg / mu of bio-organic fertilizer + 7kg / mu of humic acid slow-release fertilizer every year in the first 3 years after reseeding. The ratio of nitrogen, phosphorus and potassium is 16:10:7; A6, no-tillage reseeding + 60kg / mu of bio-organic fertilizer + composite coating of grass seeds before mixing with the grass seed composition and bio-organic fertilizer; A7, no-tillage reseeding + 60kg / mu of bio-organic fertilizer + 7kg / mu of humic acid slow-release fertilizer every year in the first 3 years after reseeding, the ratio of nitrogen, phosphorus and potassium of the slow-release fertilizer is 16:10:7 + composite coating of grass seeds before mixing with the grass seed composition and bio-organic fertilizer.

[0066] The no-tillage reseeding grass seed combination is 50% Rhizoma Cyperi + 40% Icegrass Mongolia + 10% Astragalus membranaceus, the reseeding amount is 4kg / mu, and the existing V-shaped furrow opener is used for no-tillage reseeding, the row spacing is 35cm, and the depth is 2-3cm.

[0067] The experiment adopted a randomized block design with three replicates and each plot was 100m2. 2 .

[0068] Choose late March to early April for sowing. Germinate the seeds before sowing. Soak them in warm water for 12 to 24 hours and then germinate until they turn white. Build a simple greenhouse or cover the sowing area with straw mats. The height of the simple greenhouse is 1 to 1.5 meters, and the thickness of the straw mats is 3 to 5 cm.

[0069] The grass seed composition and the biological organic fertilizer are uniformly mixed in a mass ratio of 1:15.

[0070] Use drip irrigation, with the frequency of irrigation being once every 2 to 3 days during the seed germination and seedling growth stages. Each irrigation should make the soil moist to a depth of 10 to 15 cm. Mix the water retaining agent with biological organic fertilizer and grass seeds before sowing. The amount of water retaining agent is 1% of the seed weight. Cover the sowing area with straw or mulch film, with a straw thickness of 5 to 10 cm, and the mulch film must be tightly sealed.

[0071] The coating material is composed of the following components by weight:

[0072] Humic acid chelated calcium magnesium particles loaded with attapulgite 35%, particle size 0.5-1mm, specific surface area ≥200m2 / g; polyglutamic acid-sodium alginate sustained-release film 20%, cross-linking degree controlled at 60-80%;

[0073] 6% of composite flora activator, including 0.5% of L-glutamine, 1.5% of chitosan oligosaccharide, and 0.02% of indolebutyric acid; the rest is water;

[0074] Among them, the coating weight gain rate is about 18% of the seed weight.

[0075] <Measurement Items and Data Analysis>

[0076] 1. Determination of soil physical properties

[0077] The soil bulk density was determined by the ring knife method; the soil moisture content was determined by the drying method; and the soil particle composition was determined using a laser particle size analyzer.

[0078] The measurement results are shown in Table 1 below:

[0079] Table 1 Effects of different restoration measures on soil physical properties of degraded desert grassland

[0080]

[0081] As can be seen from Table 1, different restoration measures for degraded desert grassland significantly affected soil physical properties. Compared with the enclosure control (CK), the reseeding + application of bio-organic fertilizer treatments (A2, A3, A4) significantly reduced soil bulk density by 2.85%, 4.21%, and 3.55%; compared with reseeding (A1), A4 significantly reduced soil bulk density by 2.96%; A3 reduced soil bulk density by 1.50% and 0.78% compared with A2 and A4. Compared with CK, A1, and A2, A3 significantly increased soil water content in degraded desert grassland. Compared with the enclosure control (CK), reseeding (A1) and reseeding + application of bio-organic fertilizer (A2, A3, and A4) significantly increased soil clay content; A3 significantly increased soil clay content compared with A1, A2, and A4. In short, reseeding degraded desert grasslands and applying 60kg / mu of biological organic fertilizer can significantly improve soil physical properties, reduce soil bulk density, and increase soil moisture and clay content.

[0082] A5 applied humic acid slow-release fertilizer (nitrogen, phosphorus and potassium 16:10:7) for three consecutive years on the basis of A3 (60kg / mu bio-organic fertilizer), and the soil bulk density increased from 1.31g / cm 3 Further reduced to 1.28g / cm 3(A decrease of 2.29%). The cementing effect of humic acid in slow-release fertilizers continuously enhances the stability of soil aggregates and significantly improves pore connectivity. Humic acid slow-release fertilizers increase the water content from 5.12% to 5.34% (an increase of 4.30%) on the basis of A3. Its colloidal network structure can absorb more free water while reducing evaporation losses caused by surface salt crystallization. Humic acid slow-release fertilizers promote clay flocculation by chelating calcium and magnesium ions. The clay content reaches 3.45% (an increase of 10.58% over A3), confirming the catalytic effect of humic acid on the formation of secondary minerals.

[0083] A6 uses grass seed composite coating technology (attapulgite loaded with calcium magnesium humate + polyglutamic acid sustained-release film) to reduce the bulk density to 1.27g / cm 3 (3.05% lower than A3). The high specific surface area of ​​attapulgite (≥200m 2 / g) swells under wet conditions, directly squeezing the gaps between sand particles and promoting the formation of microaggregates. The polyglutamic acid-sodium alginate film in the composite coating forms a local water retention barrier, and the water content increases to 5.41% (5.66% increase over A3). The film continuously releases water during degradation, and the ion exchange reaction with attapulgite (Ca 2 + / Mg 2 +) together enhance the soil water holding capacity. The composite bacterial flora activator (chitosan oligosaccharide + indolebutyric acid) in the coating stimulates microorganisms to secrete extracellular polysaccharides, and the clay content increases to 3.68% (17.95% higher than A3). Microbial metabolites act as "natural binders" to directly bridge sand particles to form stable clay clusters.

[0084] Under the dual intervention of slow-release fertilizer and coating in A7, the bulk density reached the lowest value of 1.25g / cm 3 (A decrease of 8.76% compared with CK, marked as e), indicating that the synergistic effect of chemical cementation (humic acid) and physical extrusion (coating material) can break through the structural improvement limit of a single measure. When slow-release fertilizer and coating are used together, the water content reaches 5.62% (an increase of 26.29% compared with CK), realizing the triple water retention mechanism of "colloid water retention + physical barrier + ion regulation", and the water utilization efficiency is significantly better than a single measure. When slow-release fertilizer and coating are used together, the clay content exceeds 4.12% (the cumulative increase in 3 years is 4.12 percentage points), indicating that the synergy of mineral cementation (slow-release fertilizer) and biological cementation (coating activator) can accelerate the lithification process of sandy soil.

[0085] 2. Soil fertility determination

[0086] During the most vigorous period of vegetation growth, 0-30cm soil samples were collected from each treatment, roots and other impurities were picked out, and then mixed through a 2mm sieve. The samples were placed in a cool place to dry naturally, and the soil organic matter, total nitrogen, total phosphorus, alkaline nitrogen, available phosphorus, and available potassium content were analyzed and determined. The organic matter content was determined by potassium dichromate-ferrous sulfate titration; the soil total nitrogen was determined by the fully automatic Kjeldahl nitrogen determination method; the soil alkaline nitrogen was determined by alkaline diffusion absorption method; the soil total phosphorus and available phosphorus were determined by molybdenum antimony colorimetry; and the soil available potassium was determined by flame photometry.

[0087] The measurement results are shown in Table 2 below:

[0088] Table 2 Effects of different restoration measures on soil fertility of degraded desert grassland

[0089]

[0090] As can be seen from Table 2, compared with the enclosure control (CK), the soil nutrient content of the degraded desert grassland increased after reseeding + application of bio-organic fertilizer, specifically increasing the content of soil organic matter, total nitrogen, total phosphorus, alkaline nitrogen, available phosphorus, and available potassium, and the best effect was achieved when reseeding + application of 60kg / mu bio-organic fertilizer.

[0091] Based on A3 (60kg / mu bio-organic fertilizer), A5 treatment applied humic acid slow-release fertilizer (nitrogen, phosphorus and potassium 16:10:7) for three consecutive years to improve soil fertility in multiple dimensions: organic matter increased to 13.52g / kg (4.32% higher than A3), humic acid stimulated the secretion of root secretions, and promoted the efficient decomposition of straw residues by microorganisms; total nitrogen reached 0.42g / kg (+7.69%), 16% of the nitrogen in the slow-release fertilizer was controlled by humic acid colloid, and the ammonia volatilization loss rate was reduced from the conventional 30% in arid areas to 18%; available phosphorus exceeded 2.06mg / kg (+13.19%), and humic acid chelated soil Fe 3 + / Al 3 + Releases fixed phosphorus while inhibiting phosphorus re-fixation. A5 optimizes the nitrogen and phosphorus supply rhythm through a chemical slow-release mechanism, allowing the available phosphorus to reach the threshold required by the species to establish the community (>2.0mg / kg), providing balanced nutrient support for short-term ecological restoration.

[0092] A6 treatment activated soil biogeochemical cycle through grass seed composite coating technology (attapulgite + polyglutamic acid film + microbial activator): organic matter jumped to 13.89g / kg (+7.17%), attapulgite (specific surface area ≥200m 2 / g) adsorbs soluble organic carbon, and chitosan oligosaccharides activate lignin-degrading bacteria to accelerate the conversion of stubborn carbon; the available potassium reaches 129.74mg / kg (+7.69%), and the natural potassium feldspar in the coating material weathers and releases potassium, which cooperates with microbial metabolites to promote potassium ion desorption; the alkaline nitrogen is increased to 18.42mg / kg (+15.01%), and the water retention effect of the polyglutamic acid film maintains the activity of nitrifying bacteria, and the nitrogen conversion efficiency is improved. A6 takes biological activation as the core, achieving an annual release of available potassium of 8.2kg / mu, which is close to the natural potassium replenishment rate in semi-arid areas (10kg / mu / year), and is suitable for medium- and long-term soil potassium reservoir reconstruction.

[0093] A7 triggers the "chemical-biological-physical" synergistic effect through the dual intervention of slow-release fertilizer + coating: organic matter surges to 14.37g / kg (+10.88%), and the positive feedback cycle of humic acid and microorganisms drives the carbon accumulation rate to 1.24g / kg / year, which is 2.5 times the natural rate; total nitrogen / alkaline-hydrolyzed nitrogen reaches 0.45g / kg and 19.63mg / kg (+15.38% / 22.53%) respectively, and the humic acid controlled-release nitrogen and the film water retention work together to increase the nitrification rate by 40% to 60%; the fast-acting phosphorus / potassium exceeds 2.34mg / kg and 133.92mg / kg (+28.57% / 11.17%), and the ion exchange of attapulgite for phosphorus solubilization + slow-release fertilizer for potassium supplementation make the stability of phosphorus and potassium supply (coefficient of variation <5%) significantly better than a single measure. A7 makes the available phosphorus and potassium reach the critical value of desert plants and the potassium abundance standard in semi-arid areas respectively, marking the transition of soil from "nutrient limitation" to "functional balance", providing a paradigm for the restoration of degraded grassland systems.

[0094] 3. Determination of soil microorganisms and enzyme activity

[0095] During the most vigorous vegetation growth period, fresh soil samples of 0-30 cm were collected from each treatment, roots and other impurities were picked out, and then mixed through a 2 mm sieve and stored in a refrigerator at 4 °C for the determination of soil microbial count, microbial biomass carbon and nitrogen, and enzyme activity. The soil microbial count was determined by plate count method, and microbial biomass carbon and nitrogen were determined by chloroform fumigation 0.5 mol / LK 2 SO 4 All soil extracellular enzyme activity assays were performed according to the instructions of the Solebol kit.

[0096] The measurement results are shown in Tables 3 and 4 below:

[0097] Table 3 Effects of different restoration measures on soil microorganisms in degraded desert grassland

[0098]

[0099] Table 4 Effects of different restoration measures on soil extracellular enzyme activities in degraded desert grassland

[0100]

[0101] As can be seen from Table 3, compared with the enclosure control (CK), the total number of soil microorganisms, microbial biomass carbon content, and microbial biomass nitrogen content of the degraded desert grassland increased after reseeding + application of bio-organic fertilizer, and the best effect was achieved when reseeding + application of 60 kg / mu bio-organic fertilizer.

[0102] In the A5 treatment (reseeding + 60 kg / mu bio-organic fertilizer + humic acid slow-release fertilizer), the total number of soil microorganisms reached 7.82×10 4 CFU / g, an increase of 23.0% over A3, and the microbial biomass carbon and nitrogen content increased to 162.37mg / kg and 26.93mg / kg respectively (an increase of 11.0% and 10.9% over A3). Humic acid slow-release fertilizer provides a stable carbon-nitrogen ratio (C / N≈25) substrate for microorganisms by continuously releasing nitrogen, phosphorus, potassium and humic acid colloid, activating oligotrophic bacteria such as actinomycetes; at the same time, the humic acid in the slow-release fertilizer combines with microbial extracellular polysaccharides (EPS) to form a stable complex, which increases the annual accumulation rate of microbial biomass carbon from 21.9mg / kg / year in A3 to 27.1mg / kg / year, and the nitrogen utilization efficiency (microbial biomass nitrogen / total nitrogen) from 6.23% in A3 to 6.41%. Along with the enhancement of carbon and nitrogen metabolism, the activity of β-glucosidase increased to 13.54 μmol / g / h (compared with A3+7.0%), and the activity of leucine aminopeptidase reached 7.85 μmol / g / h (+10.1%), indicating that the slow-release fertilizer synchronously enhanced the carbon and nitrogen cycle function by optimizing the nutrient release rhythm.

[0103] Treatment A6 (reseeding + 60 kg / mu bio-organic fertilizer + grass seed composite coating) upgraded the microbial system through the biological effect of the coating material, and the total number of microorganisms increased to 8.35×10 4 CFU / g (compared with A3+31.3%), and the microbial biomass carbon and nitrogen reached 175.64mg / kg and 28.41mg / kg (+20.0% and 17.0%) respectively. The polyglutamic acid-sodium alginate film in the coating degrades to form a microporous structure, creating the most suitable habitat for microorganisms (pore diameter 2-5μm), and increasing the abundance of rhizosphere probiotics (such as Burkholderia) by 40%-60%; the calcium magnesium humate particles loaded with attapulgite release Ca through ion exchange 2 + / Mg 2+, stimulates microorganisms to secrete alkaline phosphatase, promotes N-acetyl-β-D-glucosidase activity to 9.78μmol / g / h (compared to A3+10.5%), and promotes the transformation of stubborn organic nitrogen such as chitin. The chitosan oligosaccharide (1.5%) in the coating acts as a microbial quorum sensing signal molecule, which enhances the biofilm formation ability of the bacterial community by 2.3 times, directly improving the stability of microbial biomass nitrogen (the coefficient of variation is reduced from 0.58% of A3 to 3.13%).

[0104] A7 treatment (reseeding + 60kg / mu bio-organic fertilizer + slow-release fertilizer + coating) showed the synergistic advantages of multiple technologies, and the total number of microorganisms exceeded 9.14×10 4 CFU / g (compared with A3+43.7%), microbial biomass carbon and nitrogen reached 189.05 mg / kg and 30.76 mg / kg (+29.2% and 26.7%) respectively, and the activities of key extracellular enzymes were comprehensively improved: α-glucosidase (3.45 μmol / g / h, +36.4%) reflected the accelerated utilization of easily degradable carbon, β-glucosidase (15.07 μmol / g / h, +19.0%) marked the enhanced cellulose degradation ability, and leucine aminopeptidase (8.72 μmol / g / h, +22.3%) indicated the optimization of protein conversion efficiency. This synergy stems from the coupling of the C / N balanced substrate provided by the slow-release fertilizer and the coated microenvironment - the humic acid colloid encapsulates the nutrients to extend their retention time in the rhizosphere (half-life increases from 18 days in A3 to 25 days), while the water-holding swelling characteristics of attapulgite stabilize the rhizosphere humidity at 60%-70%, extending the active period of nitrifying bacteria from 45 days in the rainy season to 80 days. The ratio of microbial biomass carbon / organic matter increased from 11.3 in A3 to 13.1, proving that the conversion efficiency of microorganisms to organic matter has increased, marking the soil entering the self-sustaining organic matter-microorganism positive feedback cycle stage.

[0105] As can be seen from Table 4, compared with the enclosure control (CK), the degraded desert grassland increased soil α-glucosidase activity, β-glucosidase activity, N-acetyl-β-D-glucosidase activity, and leucine aminopeptidase activity after reseeding + application of bio-organic fertilizer, and the best effect was achieved when reseeding + application of 60 kg / mu bio-organic fertilizer.

[0106] In the A5 treatment (reseeding + 60kg / mu bio-organic fertilizer + humic acid slow-release fertilizer), the soil α-glucosidase activity increased to 2.89μmol / g / h (an increase of 14.2% compared with A3), and the β-glucosidase activity reached 13.54μmol / g / h (+7.0%), indicating that the slow-release fertilizer prolonged the action cycle of carbon hydrolases through the adsorption-slow-release effect of humic acid colloid on easily decomposable carbon sources (such as monosaccharides and oligosaccharides). 16% of the nitrogen in the humic acid slow-release fertilizer exists in the form of polypeptides, which stimulates the activity of leucine aminopeptidase to 7.85μmol / g / h (+10.1%), thereby improving the conversion efficiency of protein nitrogen sources; the increase in N-acetyl-β-D-glucosidase activity (9.32μmol / g / h, +5.3%) is due to the chelation of soil heavy metal ions (such as Cu 2 +、Zn 2 +), reducing the inhibitory effect on chitin decomposing enzymes. This synergistic enhancement of enzyme activity optimized the carbon-nitrogen metabolic flux ratio (C / N enzyme activity ratio) from 1.67 in A3 to 1.73, which is closer to the metabolic balance state of healthy grassland (1.8-2.0).

[0107] Treatment A6 (reseeding + 60kg / mu bio-organic fertilizer + grass seed composite coating) significantly activated the enzyme system through the biological effect of the coating material, and the β-glucosidase activity reached 14.23μmol / g / h (12.4% higher than A3), which was due to the microporous structure (pore size 2-5μm) produced by the degradation of polyglutamic acid-sodium alginate film, which increased the contact area between cellulase and substrate; the calcium magnesium humate particles loaded with attapulgite released Ca 2 +, activates alkaline phosphatase in the soil, and indirectly promotes the activity of N-acetyl-β-D-glucosidase to 9.78μmol / g / h (+10.5%). The chitosan oligosaccharide (1.5%) in the coating acts as a microbial quorum sensing inducer, which increases the activity of leucine aminopeptidase to 8.16μmol / g / h (+14.4%). Its mechanism of action includes enhancing the expression of protease encoding genes (such as lapA) and stabilizing the enzyme protein conformation. The significant increase in α-glucosidase activity (3.12μmol / g / h, +23.3%) is related to the coating material adsorbing soluble glucose to form a slow-release reservoir. This "enzyme-substrate-microenvironment" coupling effect increases carbon utilization efficiency by 18%-22%.

[0108] A7 treatment (reseeding + 60kg / mu bio-organic fertilizer + slow-release fertilizer + coating) showed comprehensive synergistic enhancement of the enzyme system. The activities of α-glucosidase (3.45μmol / g / h, +36.4%) and β-glucosidase (15.07μmol / g / h, +19.0%) reached a synergistic peak, reflecting that the easily decomposable carbon provided by the slow-release fertilizer and the microporous structure of the coating jointly extended the cellulose degradation chain reaction; the jump in leucine aminopeptidase activity (8.72μmol / g / h, +22.3%) was due to the protective effect of the humic acid-peptide complex on the enzyme active center, which extended the enzyme half-life from 4.2 hours in A3 to 5.8 hours. The improvement of N-acetyl-β-D-glucosidase activity (10.34μmol / g / h, +16.8%) depends on dual intervention: slow-release fertilizer relieves heavy metal inhibition, and the Streptomyces activated by coating secretes chitinase enhancers (such as chitin oligosaccharides). This multi-mechanism synergistic effect brings the carbon-nitrogenase activity ratio (1.79) close to the ecological threshold, marking a shift in soil metabolic function from "carbon limitation-dominated" to "carbon-nitrogen synergistically driven", which can shorten the ecological function recovery period of degraded grasslands by 30%-40%.

[0109] <Example B>

[0110] The method of the present invention was tested in a certain test area, where the annual average temperature was greater than 25°C, the annual precipitation was 100-200 mm, the test site had a uniform degradation degree, the vegetation was uniform, and the test soil was loam. The test grass species included Rhizoma Cynanchum, Rhizoma Icegrass, and Astragalus Astragali.

[0111] The experiment set up 8 treatments, namely: CK, closed control, no reseeding and no fertilization; B1, only no-till reseeding, no fertilization; B2, no-till reseeding + 20kg / mu of bio-organic fertilizer; B3, no-till reseeding + 40kg / mu of bio-organic fertilizer; B4, no-till reseeding + 60kg / mu of bio-organic fertilizer; B5, no-till reseeding + 40kg / mu of bio-organic fertilizer + 7kg / mu of humic acid slow-release fertilizer every year in the first 3 years after reseeding. The ratio of nitrogen, phosphorus and potassium is 16:10:7; B6, no-tillage reseeding + 40kg / mu of bio-organic fertilizer + composite coating of grass seeds with the bio-organic fertilizer before mixing; B7, no-tillage reseeding + 40kg / mu of bio-organic fertilizer + 7kg / mu of humic acid slow-release fertilizer every year in the first 3 years after reseeding, the ratio of nitrogen, phosphorus and potassium of the slow-release fertilizer is 16:10:7 + composite coating of grass seeds with the bio-organic fertilizer before mixing.

[0112] The no-tillage reseeding grass seed combination is 50% Rhizoma Cyperi + 45% Icegrass Mongolia + 5% Astragalus membranaceus, the reseeding amount is 3kg / mu, and the existing V-shaped furrow opener is used for no-tillage reseeding, the row spacing is 35cm, and the depth is 2-3cm.

[0113] The experiment adopted a randomized block design with three replicates and each plot was 100m2. 2 .

[0114] During the high temperatures in summer, build a shade net with a shading rate of about 60% in the sowing area; irrigate once in the morning and evening every day; conduct pest and disease inspections at least once a week and take timely prevention and control measures.

[0115] Sprinkler irrigation is adopted, and the irrigation frequency is once every 8 days.

[0116] The coating material is composed of the following components by weight:

[0117] Humic acid chelated calcium magnesium particles loaded with attapulgite 35%, particle size 0.5-1mm, specific surface area ≥200m 2 / g; polyglutamic acid-sodium alginate sustained-release film 20%, cross-linking degree controlled at 60-80%;

[0118] 6% of composite flora activator, including 0.5% of L-glutamine, 1.5% of chitosan oligosaccharide, and 0.02% of indolebutyric acid; the rest is water;

[0119] Among them, the coating weight gain rate is about 18% of the seed weight.

[0120] <Measurement Items and Data Analysis>

[0121] The same method as in Example A was adopted to measure soil physical properties, soil fertility, and soil microorganisms and enzyme activities. The results are shown in Tables 5 to 8.

[0122] Table 5 Effects of different restoration measures on soil physical properties of degraded desert grassland

[0123]

[0124] Table 6 Effects of different restoration measures on soil fertility of degraded desert grassland

[0125]

[0126] Table 7 Effects of different restoration measures on soil microorganisms in degraded desert grassland

[0127]

[0128] Table 8 Effects of different restoration measures on soil extracellular enzyme activities in degraded desert grassland

[0129]

[0130] As can be seen from Table 5, the physical properties of the soil in the degraded desert grassland were significantly improved after reseeding and application of bio-organic fertilizer. The bulk density of the B7 treatment (reseeding + 40kg / mu bio-organic fertilizer + slow-release fertilizer + coating) was reduced to 1.08g / cm 3 (a decrease of 13.6% compared with CK), the water content increased to 7.40% (compared with CK+34.5%), and the clay volume increased to 17.50% (compared with CK+75.0%). Humic acid slow-release fertilizer promotes the formation of aggregates through cementation, and the coating material (attapulgite + film) squeezes soil particles through water retention and expansion. The dual effects significantly optimize the soil structure. In addition, the shade net (shading rate of 60%) and morning and evening irrigation (average daily water supply of 2.5mm) work together to maintain soil moisture, reduce high-temperature evaporation losses, and increase the average daily water use efficiency by 18%. The annual clay generation rate of B7 reached 1.3% / year, which is nearly twice the natural rate, indicating that the soil's ability to resist wind erosion has been significantly enhanced.

[0131] The data in Table 6 show that the B7 treatment performed outstandingly in terms of soil fertility. The organic matter content reached 20.50 g / kg (64.0% higher than CK+), and the humic acid slow-release fertilizer and the activated microorganisms in the coating synergistically drove the rapid accumulation of organic matter, with an annual growth rate of 1.8 g / kg (3.6 times the natural rate). The available phosphorus (3.10 mg / kg, 158% higher than CK+) and available potassium (165.5 mg / kg, 44% higher than CK+) were significantly increased, and the humic acid chelated Fe 3 + / Al 3 + releases fixed phosphorus, attapulgite replaces phosphate to inhibit re-fixation, and the coated potassium feldspar weathers and releases potassium, with an annual supply of 5.2kg / mu. The alkaline nitrogen of B7 (27.30mg / kg) is 106.8% higher than that of CK. The humic acid slow-release fertilizer prolongs the urea hydrolysis cycle, and the water-retaining effect of the coating maintains the activity of nitrifying bacteria, significantly improving the nitrogen utilization efficiency.

[0132] Tables 7 and 8 further reveal that the B7 treatment significantly improved soil microorganisms and enzyme activities. The total number of microorganisms reached 8.50×10 4CFU / g (183% higher than CK+), microbial biomass carbon / nitrogen increased to 195.0mg / kg and 38.0mg / kg (129% / 153% higher than CK+), humic acid slow-release fertilizer provided C / N balanced substrate, coating activated probiotic proliferation, and microbial metabolites (such as EPS) formed a stable complex with humic acid. In terms of enzyme activity, B7's β-glucosidase (17.00μmol / g / h, 66.7% higher than CK+) and leucine aminopeptidase (10.00μmol / g / h, 81.8% higher than CK+) were significantly enhanced, polyglutamic acid film prolonged the enzyme-substrate contact time, humic acid slow-release fertilizer provided polypeptide substrates, and the enzyme half-life was extended to 6.2 hours. The C / N enzyme activity ratio of B7 (1.70) was close to the threshold of healthy grassland (1.8-2.0), indicating that soil carbon and nitrogen metabolism tended to be balanced and ecological functions were significantly restored.

[0133] In addition, it can be seen from the method provided by the present invention that the present invention digs trenches at a depth of 3 to 4 cm on the ground surface, and the plant roots and stems are densely distributed in the shallow layer of the ground surface. After the existing V-shaped furrow opener digs up the plant roots and stems, the plant roots and stems will hang on the furrow opener, hindering the forward movement of the furrow opener. If the forward power of the seeder is used to forcibly pull, the plant roots and stems may bring out the soil in which they are rooted, which is not conducive to maintaining the properties of the original soil and greatly reduces the no-till effect.

[0134] In order to solve the above problems, the present invention also provides a no-tillage overseeding furrow opener specially used for shallow furrowing on the ground surface, the furrow opener comprising:

[0135] A trough plate 1 is arranged vertically, and a mounting plate 2 for connecting with a seeder is arranged on the trough plate 1;

[0136] An L-shaped base plate 3, the vertical portion of which is connected to the groove of the grooved plate 1, and the horizontal portion is located below the grooved plate 1;

[0137] A pair of trenching plates 4, both connected to the top of the horizontal portion of the L-shaped base plate 3, and respectively extending downward on both sides of the horizontal portion of the L-shaped base plate 3 to form an inverted V-shaped structure for trenching;

[0138] Among them, a pair of side walls of the grooved plate 1 are provided with relative first through holes, and a rotating shaft 5 is rotatably connected in the first through hole. Both ends of the rotating shaft 5 extend out of the grooved plate 1 respectively, and a knife disc 6 is connected to both ends of the rotating shaft 5. The knife disc 6 is located above the grooving plate 4. The grooved plate 1 is also provided with a driving mechanism for driving the knife disc 6 to rotate, so that the knife disc 6 can cut off the plant roots dug up to the upper surface of the grooving plate 4.

[0139] The use process of the above embodiment is as follows: the furrow opener is connected to the seed drill, and the seeding tube is placed behind the furrow opener, and the driving mechanism is started to drive a pair of cutter discs 6 to rotate. When the seed drill moves forward, the inverted V-shaped structure digs into the shallow surface to open a furrow, and the soil brought up by the furrowing is spread to both sides along the surface of a pair of furrowing plates 4, and the plant roots and stems gradually slide toward the cutter disc 6 on the furrowing plates 4, and are then cut off by the cutter disc 6. A pair of cutter discs 6 are provided here so that the plant roots and stems in the soil in the furrowing interval can be completely cut off and separated from the main body, thereby reducing the forward resistance of the furrow opener, and at the same time preventing the plant roots and stems from being forcibly pulled out and bringing out a large amount of soil blocks.

[0140] Furthermore, the driving mechanism comprises:

[0141] A driving motor 7 is arranged on the outer side wall of the grooved plate 1, and the output shaft of the driving motor 7 passes through the side wall of the grooved plate 1 and extends into the groove of the grooved plate 1, and is coaxially connected with a first worm gear 8;

[0142] The portion of the rotating shaft 5 located in the groove of the grooved plate 1 is coaxially connected with a second worm gear 9, and the first worm gear 8 is located directly above the second worm gear 9;

[0143] A vertical partition 10 is arranged in the grooved plate 1, and the vertical parts of the first worm gear 8 and the L-shaped base plate 3 are respectively located on both sides of the partition 10. A vertical worm 11 is rotatably connected to the plate surface of the partition 10 facing the first worm gear 8 through a bracket, and the upper end of the worm 11 is meshed with the first worm gear 8, and the lower end is meshed with the second worm gear 9.

[0144] In the above embodiment, the driving motor 7 can drive the first worm gear 8 to rotate, the first worm gear 8 drives the worm 11 to rotate, the worm 11 drives the second worm gear 9 to rotate, and the second worm gear 9 drives the rotating shaft 5 to rotate, thereby causing the cutter discs 6 at both ends of the rotating shaft 5 to rotate accordingly.

[0145] Furthermore, the vertical portion of the L-shaped substrate 3 is located on one side of the groove of the partition 10 facing the groove plate 1, and a first slider 12 is slidably connected in the horizontal direction between a pair of side walls of the groove plate 1 above the L-shaped substrate 3, and the top end of the vertical portion of the L-shaped substrate 3 is rotatably connected to a first screw rod 13, the upper end of the first screw rod 13 passes through the first slider 12 and extends to above the groove plate 1, and the first screw rod 13 is threadedly connected to the first slider 12 for rotating the first screw rod 13 to adjust the vertical position of the L-shaped substrate 3.

[0146] Specifically, the first screw rod 13 can be rotatably connected to the top end of the vertical portion of the L-shaped base plate 3 in the following manner: a countersunk hole is opened at the top end of the vertical portion of the L-shaped base plate 3, and the diameter of the small hole portion of the countersunk hole is larger than the diameter of the first screw rod 13. The lower end of the first screw rod 13 is coaxially connected with a limiting column 14 adapted to the small hole portion of the countersunk hole, and the limiting column 14 is arranged in the small hole portion of the countersunk hole. The large hole portion of the countersunk hole is then connected to an annular cover plate 15, and the center hole of the annular cover plate 15 is adapted to the first screw rod 13, and the first screw rod 13 passes through the center hole of the annular cover plate 15.

[0147] Specifically, the first slider 12 can be slidably connected to a pair of side walls of the trough plate 1 in the following manner: horizontal opposing strip holes are opened on a pair of side walls of the trough plate 1, and the first slider 12 is respectively connected to a plug plate 16 on the surface of a pair of side walls facing the trough plate 1, and the plug plate 16 is inserted into the strip holes.

[0148] In the above embodiment, the upper end of the first screw rod 13 is rotated to adjust the vertical position of the L-shaped base plate 3, thereby controlling the depth of the trenching plate 4 digging into the ground. Of course, care should be taken to avoid the cutter head 6 hitting the upper surface of the trenching plate 4 during the adjustment process.

[0149] However, in the above embodiment, if the position of the trenching plate 4 is adjusted to be far from the cutter disc 6, the cutter disc 6 will only rub against the plant roots on the upper surface of the trenching plate 4, and the cutting effect of the cutter disc 6 will be weakened. In order to solve the above problem, the following further improvements are made.

[0150] Furthermore, a second slider 17 is slidably connected in the vertical direction between a pair of side walls of the grooved plate 1 in an area near the groove, and a second screw rod 18 is rotatably connected to the vertical portion of the L-shaped substrate 3 toward the end face of the groove of the grooved plate 1, and the rear end of the second screw rod 18 extends through the second slider 17 to the rear of the grooved plate 1, and the second screw rod 18 is threadedly connected to the second slider 17 for rotating the second screw rod 18 to adjust the horizontal position of the L-shaped substrate 3.

[0151] Here, the sliding connection mode between the second slider 17 and a pair of side walls of the grooved plate 1 is the same as that of the first slider 12 , and the rotational connection mode between the second screw rod 18 and the vertical portion of the L-shaped base plate 3 is the same as that of the first screw rod 13 .

[0152] In the above embodiment, the horizontal position of the L-shaped base plate 3 can be adjusted by rotating the outer end of the second screw rod 18. Since the furrowing plate 4 is raised higher the further back it is, when the L-shaped base plate 3 is close to the cutter disc 6, the distance between the cutter disc 6 and the upper surface of the furrowing plate 4 is reduced, thereby strengthening the supporting effect on the plant roots and stems, and ensuring that the cutting effect of the cutter disc 6 is not weakened. Of course, care should be taken to avoid the cutter disc 6 hitting the upper surface of the furrowing plate 4 during the adjustment process.

[0153] In order to verify the effect of the furrow opener provided by the present invention, the experimental conditions of A3 were also adopted, and the furrow opener (A3') provided by the present invention was used to conduct experiments in a small area.

[0154] The physical properties of the soil were measured, and the results are shown in Table 9 below:

[0155] Table 9 Effects of different openers on soil physical properties of degraded desert grassland

[0156]

[0157] It can be seen from Table 9 that, compared with the existing furrow opener (A3), the furrow opener (A3') provided by the present invention reduces the soil bulk density, increases the soil water content of the degraded desert grassland, and also increases the soil clay content.

[0158] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for improving the soil quality of degraded desert grassland, characterized in that: include: Evenly mix grass seeds and bio-organic fertilizers and apply them evenly to degraded desert grasslands in a no-tillage overseeding manner; The amount of grass seed to be sown is 3-4 kg / mu, and the grass seed combination is 50-60 wt% of Rhizoma Cynanchum, 40-50 wt% of Icegrass, and 0-10 wt% of Astragalus membranaceus. The application amount of biological organic fertilizer is adjusted according to the soil type: the application amount for sandy soil is 60kg / mu, and the application amount for loam is 40kg / mu; the indicators of biological organic fertilizer are: effective live bacteria count ≥5×107 / g, including Bacillus subtilis, Bacillus megaterium, and Paenibacillus gelatinosa, fulvic acid ≥12%, and organic matter ≥40%.

2. The method for improving soil quality of degraded desert grassland according to claim 1, characterized in that: Adjust irrigation according to climatic conditions: In arid areas with annual precipitation less than 100 mm, drip irrigation is used. The irrigation frequency is once every 2 to 3 days during the seed germination and seedling growth stages. Each irrigation amount should make the soil moist to a depth of 10 to 15 cm. Before sowing, water retaining agent is mixed with biological organic fertilizer and grass seeds. The amount of water retaining agent is 0.5 to 1% of the seed weight. The sowing area is covered with straw or mulch film. The straw thickness is 5 to 10 cm, and the mulch film needs to be tightly sealed. In areas with annual precipitation of 100 to 200 mm, sprinkler irrigation is used, with an irrigation frequency of once every 7 to 10 days; In addition, in areas where the annual average temperature is less than 5°C, choose to sow in late March to early April. Before sowing, germinate the seeds and soak them in warm water for 12 to 24 hours to germinate until they turn white. Build a simple greenhouse or cover the sowing area with straw curtains. The height of the simple greenhouse is 1 to 1.5 meters, and the thickness of the straw curtains is 3 to 5 cm. In areas where the average annual temperature is greater than 25°C, build a shade net with a shading rate of 50-70% in the sowing area during the high temperatures in summer; irrigate once in the morning and evening every day; conduct pest and disease inspections at least once a week and take timely prevention and control measures.

3. The method for improving soil quality of degraded desert grassland according to claim 1, characterized in that: The grass seed composition and the biological organic fertilizer are uniformly mixed in a mass ratio of 1: (5-20); The mass ratio of the three kinds of Bacillus in the biological organic fertilizer is Bacillus subtilis: Bacillus megaterium: Paenibacillus gelatinous=(3-5):(2-4):1; The raw materials for preparing the biological organic fertilizer include: 40-50% of decomposed sheep manure, 20-30% of humic acid mineral powder, 10-15% of soybean meal powder, and 5-8% of microbial agent; In the first three years after reseeding, 5-8 kg / mu of humic acid slow-release fertilizer is applied each year, and the ratio of nitrogen, phosphorus and potassium of the slow-release fertilizer is (15-18):(8-12):(5-8).

4. The method for improving soil quality of degraded desert grassland according to claim 3, characterized in that: The grass seed composition and the biological organic fertilizer are subjected to a composite coating treatment on the grass seeds before being mixed, and the coating material is composed of the following components in weight ratio: Humic acid chelated calcium magnesium particles loaded with attapulgite 30-40%, particle size 0.5-1mm, specific surface area ≥200m 2 / g; polyglutamic acid-sodium alginate sustained-release film 20-25%, cross-linking degree controlled at 60-80%; 5-8% of composite flora activator, including 0.5% of L-glutamine, 1.5% of chitosan oligosaccharide, and 0.02% of indolebutyric acid; the rest is water; The coating weight gain rate is 15-20% of the seed weight.

5. The method for improving soil quality of degraded desert grassland according to claim 3, characterized in that: The bacterial flora in the biological organic fertilizer needs to be oriented and cultivated: Stage 1: Activation in beef extract peptone medium at pH 7.0-7.5 for 24 h at 35±1°C; The second stage: transfer to the acclimation medium containing 5% decomposed sheep manure extract, and gradually increase the NaCl concentration to 1.5%, increasing by 0.3% every 12 hours; The third stage: screening stress-resistant strains under UV-microwave alternating stress, the parameters are: 254nm irradiation, 10min / microwave, 400W, treatment for 30s.

6. The method for improving soil quality of degraded desert grassland according to claim 3, characterized in that: The preparation of the biological organic fertilizer comprises the following steps: 1) Mixing the decomposed sheep manure with a C / N ratio of ≤25 and a moisture content of ≤30% with the humic acid mineral powder with an oxidation degree of ≥65% and a particle size of ≤0.075 mm at 80-90° C. for 20 minutes to form a porous matrix; 2) Premix soybean meal powder with a protein content of ≥45% with a composite bacterial agent at a ratio of 1:0.2, and spray an atomized liquid containing 0.1% rhamnolipid to form microencapsulation granules with a particle size of 2 to 3 mm; 3) The matrix obtained in step 1) and the particles obtained in step 2) are layered in a drum fermenter at a ratio of 7:3, the porosity of the pile is controlled to be ≥ 40%, the fermentation temperature is maintained at 50-55° C. for 72 hours, then cooled to 35° C. and matured for 24 hours; 4) The fermentation product is screened through 4 mesh, 10 mesh and 20 mesh and then surface modified with fulvic acid concentrate with a pH of 8.5 to 9.0, and the final moisture content is adjusted to 12 to 15%.

7. The method for improving soil quality of degraded desert grassland according to claim 1, characterized in that: When no-till reseeding, first use a furrow opener to dig furrows with a row spacing of 35 cm and a depth of 2 to 3 cm; The furrow opener comprises: A trough plate is vertically arranged, and a mounting plate for connecting with a seeder is arranged on the trough plate; An L-shaped base plate, the vertical portion of which is connected to the groove of the groove-shaped plate, and the horizontal portion is located below the groove-shaped plate; A pair of trenching plates, both connected to the top of the horizontal portion of the L-shaped base plate and extending downward on both sides of the horizontal portion of the L-shaped base plate to form an inverted V-shaped structure for trenching; Among them, a pair of side walls of the grooved plate are provided with opposite first through holes, and a rotating shaft is rotatably connected in the first through hole. Both ends of the rotating shaft extend out of the grooved plate respectively, and a knife disc is connected to both ends of the rotating shaft. The knife disc is located above the grooving plate. A driving mechanism for driving the knife disc to rotate is also provided on the grooved plate, so that the knife disc can cut off the plant roots dug up from the grooving plate to its upper surface.

8. The method for improving soil quality of degraded desert grassland according to claim 7, characterized in that: The driving mechanism comprises: A driving motor is arranged on the outer side wall of the grooved plate, the output shaft of the driving motor passes through the side wall of the grooved plate and extends into the groove of the grooved plate, and is coaxially connected with the first worm gear; The portion of the rotating shaft located in the groove of the grooved plate is coaxially connected with a second worm gear, and the first worm gear is located directly above the second worm gear; A vertical partition is arranged in the groove-shaped plate, and the vertical parts of the first worm gear and the L-shaped base plate are respectively located on both sides of the partition. A vertical worm is rotatably connected to the plate surface of the partition facing the first worm gear through a bracket, and the upper end of the worm is meshed with the first worm gear, and the lower end is meshed with the second worm gear.

9. The method for improving soil quality of degraded desert grassland according to claim 8, characterized in that: The vertical portion of the L-shaped substrate is located on one side of the partition plate facing the groove of the grooved plate, and a first slider is slidably connected in a horizontal direction between a pair of side walls of the grooved plate above the L-shaped substrate. The top end of the vertical portion of the L-shaped substrate is rotatably connected to a first screw rod, the upper end of the first screw rod extends through the first slider to above the grooved plate, and the first screw rod is threadedly connected to the first slider for rotating the first screw rod to adjust the vertical position of the L-shaped substrate.

10. The method for improving soil quality of degraded desert grassland according to claim 9, characterized in that: A second slider is slidably connected in the vertical direction between a pair of side walls of the grooved plate in an area near the groove, and a second screw rod is rotatably connected to the vertical portion of the L-shaped substrate toward the end face of the groove of the grooved plate, and a rear end of the second screw rod extends through the second slider to the rear of the grooved plate, and the second screw rod is threadedly connected to the second slider for rotating the second screw rod to adjust the horizontal position of the L-shaped substrate.

Images